Device for determining the epinasty response of plants



Sept. 26, 1944- P. w. ROHRBAUGH DEVICE FOR DETERMINING THE EPIN'ASTY RESPONSE OF PLANTS Filed Feb. 24, 1942 2 Sheets-Sheet 1 .M/VENTOR De/cg W Po/irbaug/v Sept. 26, 1944. w RQHRBAUGH 2,358,881

DEVICE FOR DETERMINING THE EPINASTY RESPONSE OF PLANTS Filed Feb. 24, 1942 2 Sheets-Sheet 2 7/ 3 //vv/v70,Q

Percy 144 Po/rbaugfi Patented Sept. 26, 1944 DEVICE FOR DETERMNING THE EPINASTY- I RESPONSE OF PLANTS Percy .W. R-ohrbaugh, Upland, C'alif., assignor to California Fruit Growers Exchange,

Los ,An-

geles, Califl, a corporation of California Application February 24, 1942, set-a1 No. 432,103

7 Claims. (01. 78-482) This invention relates to a device'to be used in connection with the testing of various atmospheres for the presence of ethylene and other gases. More particularly, the invention relates to a device in which plants showing epinastic response may be grown for the purpose of testing fruit storage atmospheres for the presence or absence of ethylene.

The storage of citrus fruits, and more particularly lemons, presents a number of problems, not the least of which is the curing of the fruit in storage over comparatively long periods of time without incurring'duringthis storage period substantial shrinkage,withering, decay, loosening of buttons, and over-coloration.

Lemons are ordinarily picked while they still have a green color but after they have reached the desired size. lhe green fruit is stored in 7 storage rooms, commonly basements, for a period of from several weeks to several months, during which certain internal curing takes place which makes the juice of the fruit more readily available,.and, in addition, thegreen colored lemons gradually change to the desired lemon-yellow color. During the curing or storage period, the

respiratory action of the fruit continues, although to a lesserextent than when the fruit is on the tree. As a result of the respiration of the fruit,

carbon dioxide and other gaseous end-products are given off, and some of these in turn tend tov accelerate the curing of the fruit, as well as the developmentof the yellow color.

Also, during the storage period some lemons decay as a result of mold. infection. It is now believed that a considerable amount of ethylene is given off by the decaying lemons and that at times the concentration of ethylene in the storage atmosphere becomes sufficient to promote more rapid coloring'of the fruit.

In addition to the gases which accumulate in the storage atmosphere from the normal respiration of the fruit and as a result of the decaying fruit, it is believed that ethylene and other gases find their way into the lemon storage rooms from other sources. For example, in packing houses where oranges are being ethylene colored in one part of the packing house and lemons stored in another part of the same house, the ethylenecontaining air finds its way into the lemon storage rooms, either from natural causes oris drawn in when the lemon storage atmosphere is recon ditioned. "Also, in those packing houses situated adjacent to busy highways, a considerable amount of automobile exhaust-gases containin fects on the fruit, and when these have already occurred it is obviously. too late to take precautionary measures .to prevent or counteract them. There has, moreover, been" no simple and satisfactory means for determiningthe presence of ethylene .in-the storagerooms. Gas analysis of the storageatmospherecould, of coursabe undertaken, but this not'only 'involves elaborate equipment but the employment of highly skilled technicians It has been'known for some time that petioles of leaves of many plants, growmore rapidly on the upper sides in atmospheres bearing ethylene. This peculiar response of'certain plants to the presence of ethylene is referred to as chemotropism or an. epinastic -response. Tomato plants, castorbeans, potato sprouts, and pea plants, especially those which have been grown in darkness will-'whenplaced in an ;a-t mosphere containing ethylene evidence chemotropism. When pea seedlings, for example, are placed in an atmosphere containing ethylene, their growth is stunted and the growth that does continue tends to assume a horizontal direction,

Heretofore, it has not beenpossible to takeadvantage of the sensitivity of those plants showis necessary. I

storage atmosphere around the growing plants ethylene,-

tures are considerably above the storage tempera have, therefore, invented a device by' means of which plants showing epinastic response may be grown in the absence of light and in the presence of circulated air and at temperatures favorable for plant growth. Accordingly, an object of this invention is to provide and disclose means for growing plants in the absence of light and at a temperature conducive to maximum plant growth, while at the same time maintaining continuous circulation of air past the growing plant.-

Another object of this invention is to provide and disclose means for using epinasty responsive plants for the determination of the presence or absence of ethylene.

heating element 24 ordinarily rests on the base plate II, and may be of any desired type which These and other objects, uses, and advantages of this invention will become apparentto those skilled in the art as the description proceeds in connection with the accompanying drawings, in which: i

Fig. 1 is a vertical, cross-sectional view of the device.

Fig. 2 is an elevation of the device.

Fig. 3 is a horizontal, cross-sectional view of the device taken along the line 3-3 of Fig. 2.

Fig. 4 is a'vertical, cross-sectional view of the cap.

Fig. 5 is a vertical, cross-sectional view of the collar showing an'additional and optional construction not shown in Fig. 1.

Corresponding and like parts in the drawings are referred to in the following description and are indicated i all views by the same reference numbers;

Referring now to the drawings in detail and particularly to Fig. 1, it will be apparent that the embodiment of the invention which is illustrated comprises a cylindrical housing III which has attached thereto and is supported by a base plate II. An upstanding annular baffie l2 surrounding and spaced from the cylindrical housing I0 is attached at right anglesto the base plate I I. A series of air intakes l3 are formed around the periphery of the cylindrical housing Ill adjacent to the base plate I I. An'annular ring I4 attached at right angles to'the cylindrical housing In is adapted to extend out over the annular bafile I2. Depending from thering I4 and at right angles thereto is an annular skirt I5. shown in Fig. 1, the parts I2, l4, and I5 are constructed to form a light-maze to prevent passage of light to the interior of the cylindrical housing by means of the air intakes l3.

Fig. 5 shows more clearly the detail of the collar IS with a neck ll. It also shows an additional construction in which a baffle plate I8 is attached below the opening of the neck IT -so as to provide further light exclusion wheredesired. This baflle plate is not regarded as essential for many uses and is not shown in Fig. 1. The collar is adapted tobe positioned over the upper end of the cylindrical housing I0.

A cap, details of which may be readily seen by referring to Fig. 4, is constructed so as to fit tightly over the neck I! of the collar I6. The main body I9 of the cap is of greater length than the neck ll of the collar so that the top of the cap will be held above and away from the top of the neck H, the reasons for whichwill become apparent hereinafter; A series of air outlets 2| is formed around the upper periphery of the-main body of the cap I9. The annular skirt 23 surrounding and positioned away from. the main body of thecap I9 depends from the top 20 of the cap in-a manner adapted to form a light-maze for the air outlets 2|. It will be seen by again;

will satisfactorily maintain the temperature of the contents of the device and the atmosphere passing therethrough at a temperature of about 78 F. In the drawings, I have shown the heating element 24 to be an electric light bulb, this in turn encased within a light-shield 26. Actually, in practice I have found that two l5-watt carbon element light bulbs wired in series and enclosed within collapsible metal tubes are satisfactory to maintain the temperature within the proper range for growing the test plants when the device is used in storage rooms wherein the temperature range is maintained between and 58 F. Obviously in this connection the temperature of the contents of the device and the atmosphere passing therethrough may be controlled within the desired temperature range by means of a thermostat operating inconjunction with. the heating element.

A small opening 21 in the side of the cylindrical housing ID is providedto admit the electric cord 28 carrying the necessary current for the heating element. This opening will, of course, be made light-proof. y

A table 29having legs 3!! is positioned within the housingand is adapted to support the container 3i within which the test plants are grown.

As is clearly referring to 1 that when the cap is in posi The device illustrated in thedrawings may be made in accordance with the following description, although it is to be understood that many modifications in the type and kind of materials used in its construction may be made Without departing from the general principles set forth. For example, I choose to construct the housing of the device in a cylindrical shapef since I believe this shape is advantageous in that itpermits better and more uniform circulation of the air through the device than one which is ofsorne other shape. In the following description of the construction of my device, I refer to specific dimensions, but this is done mr'ely for the purpose of disclosing to those skilled in the art a satisfactory size. Such dimensions are important only in that they give the general relationship of the size of the various parts of the device. For use in testing the atmosphere of storage rooms, I have found that a very satisfactory device may be made in accordance with the following description. I

For purposes of economy and ease of fabrication, I choose to construct my device from 20 gauge galvanized iron. Obviously, other materials could be used, but for my purposethe galvanize-d iron is satisfactory. The cylindrical housing III, which is about six and one-half inches indiameter, should be from twelve to fifteen inches in height to give ample room for the test plants to grow. The base plate II which supports the cylindrical housing should be about thirteen inches in diameter. The; annular bafiie I2 surrounding the cylindrical housing I0 is usually spaced about one inch therefrom and is from about one to one andz one-half inches in height. I'have found that'the series'ofair in takes 13 permits adequate circulation of airif 'ous'gasconcentrations adjacent tohighways; I In the holes areabout one-half inch in diameter and spaced around the periphery of the housing about one-half'inch apart. The {ring 14, which is at tached at right anglesfto the'cylindricaphousing' I should "extend" therefrom about two and o e half to three inches, while the skirt-l depending from'the ring shoifldometo' within about one half to thre -quarters of'an incli of the base plate 1 I.- Itis pointed "ou'tatthistime that-the lightmaze comprising theparts' l2; 'ltan'dr l5 should be so related to each other so as to excludesubstantially all the" light which mightenter through the air inlets I 3 without :rnateriall y impedingthe; circulation of the air-therethrough. "I have found it desirable to paint the surfaces of these parts so that reflection of-li'ght therefrom is materially reduced. It may be found desirable, when using plantsexceptionally sensitive to light or in the presence of a strong external light source, to complicate the light-maze byadding additional skirts and 'bafiles similar to those shown.

The collar [6 is constructed so as to fit snugly over the upper end of the cylindrical housing In. I choose to make the neck I! of the collar of such size that a standard three-inch stove pipe may be interposed between the neck I! and the main body of the cap I9, since for certain types of work I find it desirable to increase the circulation of air through the housing by using an elongated neck or stack.

The cap is constructed so as to fit over the neck II. The main body IQ of the cap may preferably be about two and one-half to three inches in length, care being taken that this portion of the cap is of greater length than the neck H, which I usually make not over two inches high. The air outlets 2i formed around the upper periphery of the main body of the cap may be about one-quarter of an inch in diameter and spaced about one-half inch apart. The annular skirt 23 surrounding the main body of the cap I9 is positioned therefrom about one-half inch and depends from the top about two inches.

The table 29 may be of any convenient size to fit loosely within the cylindrical housing. I have found that a circular table of about five inche in diameter with four legs about one and onehalf inches high and an inch in width, all being constructed outof galvanized iron, makes a satisfactory support for the containers in which the test plants are growing. 7

As mentioned before, this device is used in connection with plants showing epinastic response for the purpose of determining the presence or absence of ethylene in various atmospheres, and, particularly, those atmospheres within fruit storage chambers. If it is decided to test the atmosphere in a storage room for the presence of ethylene, a can of pea seedlings which have been germinated and grown in the dark until they are about one or two inches high, is placed on the table in the device. The device with the test plants therein is placed in a suitable location in the storage room and the heating element connected to a 1l0-volt electric service outlet. The test plants are permitted to continue growth in the device for a period of from two to four days. If ethylene is present in the storage atmosphere,

such cases a heating element-probably will not be needed, if the outside temperature is not materially below the growing te mperaturerange for the test'plants."

Having thus described my invention ins'uch clear, concise, and exact terms asto enable others skilled in theart to perform the same; I claima's my invention an d desire 'to-secure by;Letters'Patexit the followingl I '1. A device useful-in determining the epinast'y response of plants comprising a 'cylindricalhouse ing of light-impervious material supported by a base plate, saidhousi'n-g having a series of air 'intakes i'ormed around the periphery thereof ad jacent to the base plate, a baffle surrounding the housing at right angles to the base plate, said bafile extending above the tops of the aforesaid air-"intakes, anannular ring-attachedat right angles to the'housing and adaptedto-extendout bver said battle, a skirt depending atrig ht angles from said annular ring beyond the baflle and telescopically covering a major portion thereof and in spaced relation thereto, a collar positioned over the upper end of the housing, said collar having a neck portion adapted to support a tightly fitting cap, a cap having a. main body portion, with a series of air outlets formed around the upper periphery thereof, a skirt positioned away from the main body of the cap and adapted to shield the air outlets thereof, said cap being so positioned on the neck that the air outlets are not closed thereby, and a supporting means within the housing adapted to support the test plants.

2. A device useful in determining the epinasty response of plants comprising a cylindrical housing of light-impervious material supported by a base plate, said housing having a series of air intakes formed around the periphery thereof adjacent to the base plate, a bafile surrounding the housing at right angles to thebase plate, said baflle extending above the tops of the aforesaid air intakes, an annular ring attached'at right angles to the housing and extending outwardly therefrom, a skirt depending from said annular ring to a point below the top of said bafile and in spaced relation thereto, a collar positioned over the upper end of the housing, said collar having a neck-portion adapted to support a tightly fitting cap, and a cap, said cap having main body portion with a series of air outlets formed around the upper periphery thereof and a skirt positioned away from the main body of the cap and adapted to shield the air outlets thereof, said cap being so positioned on the neck that the air outlets are not closed thereby.

3. A device useful in determining the epinasty response of plants, comprising a housing of lightimpervious material having a series of air intakes around the peripher of the bottom thereof, a

- light-maze surrounding the said air intake in the test plants will be stunted, grow over sideways,

or both. 7

Under certain circumstances it may be desirable to use this device apart from or outside of v storage chambers as, for example, in testing varisuch a manner as to exclude light from entering into the device through the air intakes but adapted to permit the passage of air thereinto, means for covering the housing to exclude light from the inside thereof, said means having air outlets therein, means within said housing adapted to maintain the temperature of the device and the air passing therethrough within a predetermined range.

4. A device useful in determining the epinasty response of plants, comprising a housing of lightv impervious material having a series of air intakes around the periphery of the bottom thereof, a light maze surrounding the said air intakes in such a manner as toexclude light from entering into the device through the air intakes, but adapted to permit the passage of air thereinto; means for covering the housing to exclude light from the inside thereof, said means having air outlets therein. j

5. A device useful in determining the epinasty response of plants comprising a housing of lightimpervious material having a :series of air: intakes around the periphery of the bottom thereof, a light maze surrounding the said air intakesin such a manner as to exclude lightfrom entering into the device through the air'jintakesvv but adapted to permit the passage. of air thereinto, means'for covering the housingeto exclude vlight from the inside thereof, said means; having. air outlets therein, and means for efiecting a circula tion of airin the housing. r v 5 a Y 6. A device useful in determining theyepinasty response of plants comprising a housingof light? impervious material, said device having vmeans to admit an adjacent the "bottom thereof, lightexcludingmeans covering said air-admitting means insucha manner as to exclude light from entering into the device through the airadmitting means but adapted to permit passage of air thereint airoutlets adjacent the top of the said device, and light-excluding means covering said air outlets in such a. manner as to exclude light fromentering into the device therethrough.

7. A' device useful in determining the epinasty response of plants comprising a housing of lightimpervious material, said device having means to admit ,airgadjacent the bottom thereof, lightexcluding means arranged so as to prevent admission vof light through said air-admitting means, air outlet means adjacent the top of the device, and light excluding means so arranged as to prevent admission of light through said air outlet means.

PERCY W. ROHRBAUGH. 

